是否确定申报异步方法返回void沉默CS4014警告？ [英] Is it OK to declare an async method as returning void to silence the CS4014 warning?

问题描述

Visual Studio中发出此code警告（因为这个呼叫没有等待，目前的方法执行之前完成呼叫继续'）

Visual Studio emits a warning for this code ('because this call is not awaited, execution of the current method continues before the call is completed').

static void Main(string[] args)
{
    FireAndForget(); // <-- Warning CS4014
    // Do something else.
}

static async Task FireAndForget()
{
    // Do something (cannot throw).
}

我的理解是，这是确定不等待任务在这个特殊的情况，因为FireAndForget绝不会抛出异常。

My understanding is that it is OK not to wait for the task in this particular case because FireAndForget will never throw an exception.

而不是用编译禁用警告，我正在考虑改变从任务FireAndForget的返回类型为void。这有效地沉默的编译器。

Instead of disabling the warning with a pragma, I was considering changing the return type of FireAndForget from Task to void. That effectively silences the compiler.

static async void FireAndForget() // <-- Task changed to void
{
    // Do something (cannot throw).
}

不过，根据斯蒂芬·克利，异步无效的方法应尽量避免，所以我不太清楚该怎么做。

However, according to Stephen Cleary, 'async void' methods should be avoided so I am not quite sure what to do.

是否确定有一个'异步无效的方法，如果方法不设计成awaitable摆在首位，如果没有，会引发异常？

Is it OK to have a 'async void' method if the method is not designed to be awaitable in the first place and if no exception will be thrown?

推荐答案

这是的非常的难得有一个真正的发射后不管操作;即，操作，其中：

It's extremely rare to have a true fire-and-forget operation; that is, an operation where:

• 当它完成无人问津。


• 如果它完成无人问津。


• 如果它抛出一个异常，没有人问津。

特别地与最后的这些;大多数所谓的发射后不管作战实际上不是发射后不管，因为一些动作需要采取，如果它不会成功。

Particularly with the last of these; most so-called "fire-and-forget" operations are not actually fire-and-forget because some action needs to be taken if it doesn't succeed.

不过，也有少数情况下真正的发射后不管是适用的。

That said, there are a few situations where a true fire-and-forget is applicable.

我preFER使用异步任务和分配任务到其他未使用的变量避免编译器警告：

I prefer to use async Task and avoid the compiler warning by assigning the task to an otherwise unused variable:

var _ = FireAndForget();

异步任务方法比异步无效方法的可重用性和可测试性。

async Task methods are more reusable and testable than async void methods.

不过，我不会发脾气，如果只是用我的团队的开发人员异步无效代替。

However, I wouldn't throw a fit if a developer on my team just used async void instead.

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